Sexually Transmitted Infections (STIs)

What groups are most at risk for acquiring an STI?

While anyone can become infected with an STI, certain groups, including young people and gay and bisexual men are at greatest risk.8

CDC estimates that nearly 20 million new sexually transmitted infections occur every year in this country.8

Young people (ages 15-24) account for 50% of all new STIs, although they represent just 25% of the sexually experienced population.8

Both young men and young women are heavily affected by STDs — but young women face the most serious long-term health consequences. It is estimated that undiagnosed STDs cause 24,000 women to become infertile each year.8

Compared to older adults, sexually active adolescents 15-19 years of age and young adults 20-24 years of age are at higher risk for acquiring STIs for a combination of behavioral, biological, and cultural reasons.9

The higher prevalence of STIs among adolescents reflects multiple barriers to accessing quality STI prevention services, including lack of insurance or other inability to pay, lack of transportation, discomfort with facilities and services designed for adults, and concerns about confidentiality.9

What are the rates and trends of chlamydia and gonorrhea for adolescents and young adults?

While surveillance data show signs of potential progress in reducing chlamydia and gonorrhea among young people aged 15–24, both the numbers and rates of reported cases of these two diseases continue to be highest in this group compared to other age groups.8

Most reported chlamydia and gonorrhea infections occur among 15-24 year olds.8

Chlamydia

In 2013, 949,270 cases of chlamydial infection were reported among persons aged 15–24 years of age, representing 68% of all reported chlamydia cases.6

Among those aged 15–19 years, the rate of reported cases of chlamydia increased 6.4% during 2009–2011, decreased 4.4% during 2011–2012, and decreased 8.7% during 2012–2013. Among those aged 20–24 years, the rate increased 16.1% during 2009–2011 and remained stable during 2011–2013.6

Females

Among women aged 15–24 years of age, the population targeted for chlamydia screening, the overall rate of reported cases of chlamydia was 3,340.8 per 100,000 females. Rates varied by state, with highest reported case rates in the South.6

In 2013, the chlamydia case rate among women aged 15–19 years was 3,043.3 cases per 100,000 females, an 8.7% decrease from the 2012 rate of 3,331.7 cases per 100,000 females. Decreases in rates of reported cases were largest among 15-, 16-, and 17- year old females.6

Women aged 20–24 years had the highest rate of chlamydia in 2013 (3,621.1 cases per 100,000 females) compared with any other age and sex group. The overall chlamydia case rate among women in this age group remained stable during 2012–2013; however, rates of reported chlamydia increased among 23- and 24- year old females.6

Males

The chlamydia case rate for men aged 15–19 years decreased 9.0% from 785.8 cases per 100,000 males in 2011 to 715.2 cases per 100,000 males in 2013.6

In 2013, as in previous years, men aged 20–24 years had the highest rate of chlamydia among men (1,325.6 cases per 100,000 males). The chlamydia rate for men in this age group remained stable during 2012–2013.6

Gonorrhea

During 2012–2013, the rate of reported gonorrhea cases decreased 11.6% for persons aged 15–19 years and decreased 1.9% for persons aged 20–24 years.6

Females

In 2013, women aged 15–19 years had the second highest rate of gonorrhea (459.2 cases per 100,000 females) compared with other females. Gonorrhea rates for women in this age group decreased 12.9% from 2012–2013.6

In 2013, women aged 20–24 years had the highest rate of gonorrhea (541.6 cases per 100,000 females) compared with any other age or sex group. Gonorrhea rates for women in this age group decreased 4.7% from 2012–2013.6

Among women aged 15–24 years, the overall rate was 501.6 per 100,000 females. Rates varied by state, with highest reported case rates in the South.6

Males

In 2013, the gonorrhea rate among men aged 15–19 years was 220.9 cases per 100,000 males. Gonorrhea rates for men in this age group decreased 8.9% from 2012–2013.6

In 2013, as in previous years, men aged 20–24 years had the highest rate of gonorrhea (459.4 cases per 100,000 males) compared with other males. Gonorrhea rates for men in this age group increased 1.3% from 2012–2013.6

What are the rates and trends of other STIs for adolescents and young adults?

Young people aged 13–24 accounted for about 21% of all new HIV diagnoses in the United States in 2011.3

Though rates of HIV are very low among adolescents, males make up more than two-thirds of HIV diagnoses among 13- to 19-year-olds.3

Nationwide, 13% of students had ever been tested for HIV, not including tests done when donating blood.12

The prevalence of having been tested for HIV was higher among female (14.6%) than male (11.2%) students. The prevalence of having been tested for HIV did not change significantly from 2011 (12.9%) to 2013 (12.9%).12

The rates of syphilis among females aged 15–19 years increased annually during 2004–2009 (from 1.5 cases to 3.3 cases per 100,000 females), but decreased every year since 2010 to 1.9 cases in 2013.6

The rates of syphilis among females aged 20–24 years increased annually during 2006–2009 (from 2.9 to 5.5 cases per 100,000 females). The rate decreased from 5.5 to 3.7 cases during 2009–2011, then increased slightly (from 3.7 to 3.9 cases) during 2011–2013.6

The rates of syphilis among males aged 15–19 years increased annually during 2002–2009 (from 1.3 to 6.0 cases per 100,000 males). The rate decreased to 5.5 cases in 2010 and 2011, then increased to 5.8 cases (in 2012) and 6.4 cases (in 2013). In 2013, the rate among males aged 15–19 years was the highest reported since 1995.6

The rates of syphilis among men aged 20–24 years increased annually during 2000–2013 (from 4.3 to 27.7 cases per 100,000 males). Men aged 20–24 years had the highest rate of P&S syphilis among men of any age group during 2008–2012, barely surpassed by men 25–29 years in 2013 (28.0 cases). In 2013, the rate among men aged 20–24 years was the highest reported since 1992.6

Human papillomavirus (HPV) is the most common sexually transmitted infection.13

Over 14 million people acquire Human Papilloma Virus annually. Nearly every sexually active adult will get HPV at some point in their lives.4

There are HPV strains that increase the risk of future cervical, anal and oral cancers, and those that cause genital warts or other lesions.4

The CDC estimates that one out of every six people aged 14 to 49 years have genital herpes.7

What vaccines exist for viral STIs?

To date, there are vaccines for only two viral STIs: hepatitis B and human papillomavirus (HPV).11

Two HPV vaccines—Gardasil and Cervarix—are currently available, and both prevent the types of infections most likely to lead to cervical cancer. The Centers for Disease Control recommends HPV vaccinations for both girls and boys, starting at age 11.2

HPV vaccine uptake in the U.S. remains lower than the Healthy People 2020 goal of 80% coverage.10

In 2013, a national survey found that 57% of girls aged 13–17 years had received at least 1 dose of the HPV vaccine series, but only 38% had received all 3 doses in the series. Vaccine uptake is much lower among boys.14

What are the most effective ways of reducing the risk of contracting an STI?

The three most effective ways to avoid sexual transmission of STIs are to abstain from all sexual activity; to be in a long-term, mutually monogamous relationship with a partner who does not have an STI; and to use condoms consistently and correctly.1

All three of the most effective STI prevention strategies rely on the knowledge, behavior and interpersonal skills of the individuals. Education helps young people who are not ready for sex to withstand pressure to become sexually active and equips them with the information and skills they need to have healthy, responsible and mutually protective relationships when they do begin having sex.1

Consistent and correct use of male latex condoms can greatly reduce, though not eliminate, the risk of STI transmission. Condoms, when used consistently and correctly, are very highly effective in preventing the sexual transmission of HIV. Similarly, latex condoms reduce the risk of many other STIs that are transmitted by genital secretions such as semen or vaginal fluids, and to a lesser degree, genital ulcer diseases. Condom use also reduces the risk of HPV infection and HPV-associated diseases, such as genital warts and cervical cancer.1

Female condoms give women shared responsibility of the condom in addition to reducing the risk of STIs including HIV.5

4 Centers for Disease Control and Prevention. (2013, February). Incidence, prevalence, and cost of sexually transmitted infections in the United States.. Retrieved from http://stacks.cdc.gov/view/cdc/13174/